Airplane stabilizer



Mmc El, 1942. R. A; oPNsHAw l lAIRMANE STABILI'ZER Filed May 1, 1939 :s sheets-sheet 1 @f myfww.

ATTO R N EYS March 31,1942.

R. A. oPENsHAw AIRPLANE STABQILIZER Filed May 1, 1939 3 Sheets-Sheet 2 ATTOR N EYS March 31, 1942.

R. A. oPENsHAw. 2,278,015 AIRPLANE sTABlLIzER 3 Sheets-Sheet 5 ,Filed May l, 1939 ATTORNEYS Patented Mar.` 31, 1942 UNITED STATES PATENT QFFICE 2,278,015 AiRPLANE STABILIZERY Ralph A. penshaw,Mesa, Ariz. Application May 1, 1939, Serial No. 271,136

7 Claims.

My invention relates to airplanes, and has among its objects and advantages the provision of an improved stabilizer.

An object of my invention is to provide an automatic stabilizer embodying power actuated means for automatically maintaining an airplane at level ight, which means function to automatically return the airplane to a level position after deviating from such flight, wherein I provide gravity sensitive means for setting the power operators into motion. The gravity sensitive means is of sufficient weight to properly and efficiently set the power means into operation, but the power means functions to actuate the ailerons and elevators of the ship without aid from the gravity sensitive means, so that the latter may be of relatively small proportions and weight. My power actuated means employs power from the engine of the ship for actuating the ailerons, and motors are incorporated in the plane for actuating the elevators.

In the accompanying drawings:

Figure 1 is a perspective view diagrammatically illustrating an airplane embodying my stabilizer;

Figure 2 is a view taken from the position indicated by line 2-2 of Figure 1 but considerably enlarged;

Figure 3 is a view takenfrom the position indicated by line 3-3 of Figure 2;

Figure 4 is a sectional view along the line 4-4 of Figure 3;

Figure 5 is an enlarged sectional view of the bearing mount for one of the gravity sensitive elements; v

Figure 6 is a sectional view along theline 6-6 of Figure 5;

Figure 7 is a sectional detail view of a modified bearing mount for one of the gravity sensitive elements; and

Figure 8 is a sectional view substantially along the line 8-8 of Figure 7.

In the embodiment selected to illustrate my invention, I make use of gravity sensitive elements I6 and I2 located in the wings I4 near their outer ends, and gravity sensitive element I8 located in the fuselage 26, preferably near its rear end. Inside the fuselage 26 I mount a stabilizing mechanism 22 which is actuatedthrough the medium of the elements I6 and I2 for actuating the ailerons 24 and 26. Element I8 sets a power mechanism 28 into operation for actuating the elevators 30. Power unit 22 derives its power from the engine of the airplane, while unit 28 may comprise electric motors provided with a circuit having a switch mechanism actuated by the element I8 for selectively opening and closing the circuits of the respective motors.

Figure 2 illustrates a portion of a shaft 32 which comprises an extended end of the crankshaft of the engine. Shaft 32 isjournaled in bearings 34, and the pinion 36 keyed to the shaft is in mesh with a pinion 38 keyed on a shorter shaft 46 journaled in bearings 42. tion wheel 44 is keyed to the shaft 32, and a similar friction wheel 46 is keyed to the shaft 46, which friction wheels are spaced slightly so as to have no contact one with the other.

A bar 48 is slidable between walls 56 and 52, which walls are interconnected by a floor 54, Figures 2 and 4 illustrate roller bearings 56 as being located underneath the bar 48 to lend free and easy movement thereto. Shafts 58 and 60 are journaled in bearings 62 on the bar 48, and fiber friction Wheels 64 and 66 are respectively keyed to the shafts 58 and 66'. Normally the wheels 64 and 66 are spaced slightly from their respective drive wheels 44 and 46, but the wheels 64 and 66 rmay be independently brought into driving relation with their respective wheels 44 and 46 through shifting of the bar 48. Walls 56 and 52 are provided with elongated openings 68 through which the shafts 58 and 66 move freely as the` bar 48 is moved. I provide roller bearings 16 which extend across the upper face of the bar 48 for holding the same in place.

A pinion I2 is keyed to the shaft 58, and a similar pinion I4 is keyed to the shaft 66, both of which pinions are arranged in mesh with a rack 'I6 slidable between the wall 52 and a wall 18, see Figure 4. To the ends of the rack 'I6 I conneet control cables 86 which pass over pulleys 62 and 84 to be extended longitudinally of the wings for passage about pulleys 86 and 8l for connection with the horns 88 associated with the ailerons 24 and 26. These horns are also connected with a control cable 96 which passes around pulleys 92 and 94. Rack 'I6 moves-longitudinally between the walls 52 and 18, which walls are interconnected by the bottom 54, between which bottom and the rack I position roller bearings 96. The ends of the rack 'I6 are also vconnected with cables 98 which pass around pulleys |06 for connection with the control stick |62 of the usual type.

Gravity sensitive elements I6, I2 and I8 are identical in construction so that the description of one will apply to all. Figures 5 and 6 illustratethe 'element I6, which element includes a rack I64 arranged in mesh with a segmental gear A fiber fricf |06 arranged for rotation about the shaft |08 having its ends riveted at to the guide plates 2 between which the rack |04 is positioned. To the segmental gear |06 I connect a weight I|4 which tends to assume a vertical position and which oscillates about the axis of the shaft |08 through any tilting action of its associated wing |4 about a transverse axis, or rotation of the airplane about the longitudinal axis of the fuselage 20. Oscillation of the weight ||4 imparts reciprocatory motion to the rack |04, and this rack has one end connected with a rod ||6, which rod is provided with a ball 8 fitting loosely inside the socket on one end of a control rod |22 having its other end connected with one end of the bar 48, as at |24 in Figures 1 and 2. Referring to Figure 3, it will be lnoted that the gravity sensitive elements l0 and |2 are connected with the bar 48, and that the elements have their racks |04 arranged in axial alignment so that oscillatory movement of the two weights 4 will move the control rods |22 in the same direction, so that the units I0 and |2 function as a common unit with respect to the bar 48.

In Figure 5, plates |12 support roller sleeves |26 which engage the upper and lower faces of the rack for guiding the same. The plates are additionally secured in spaced relation through the medium of a shaft |28. Plates ||2 include arms |30 cast integrally with tapered bearing heads |32 supported by roller bearings |34 housed in the bearing retainers |36 carried by supports |38 incorporated in the wing structure of the airplane. It will thus be seen that rack |04 is mounted for rotation about its longitudi- ,A

nal axis so that the weight I I4 may always take a vertical position with respect to any shift of the airplane about a transverse axis. In this way the weights I4 are assured free movement.

The rods |22 ride on grooved wheels |40 and are bent to provide right-angular reaches |42, the lower ends of which are connected at |24 with the .bar 4B. Rotation of the airplane about its longitudinal axis in the direction of the arrow |44 of Figure 1 will cause the rods |22 to be moved to the right for moving the bar 48 in the corresponding direction. Such movement of the bar 48 will bring the friction wheel 66 into frictional relation with the friction wheel 46,

which is driven through the medium of the pinr shift the rack 16 in the opposite direction and' again actuating the ailerons 24 and 26 in the usual manner. It will thus be seen that the gravity sensitive elements |0 and |2 actuate the wheels 64 and 66 for selectively bringing the, same into engagement with their respective driv` ing wheels 4.4 and 46, so that power from the shaft 82 is utilized for'manipulating the ailerons 24 and 26. Wheels 64 and 66 in combination with their drive wheels 44 and 46 may be considered as clutches with the elements l0 and 2 functioning as clutch actuating means only. Ac,- cordingly, I make use of power means for operating the ailerons vso that the gravity sensitive means need not perform any function in the actual` manipulation of the ailerons.

Thus the gravity sensitive means may be designed so as to have sufcient power to operate the clutch mechanism only, and the burden of manipulating the ailerons is performed by power means separate and apart from the gravity responsive mechanism. My invention is associated with conven tional control wires and ailerons, which ailerons may .be manipulated manually independently of the automatic mechanism through the medium of the control stick |02,

To render the automatic mechanism inoperative as when desiring manual control, I provide a pin |48 which is slidably supported by a bracket |50 arranged to project through an opening in the wall 54 to bring its end into the opening or bore |52 in the bar 48. Pin |43 carries a head |54 against which one end of a compression spring |56 abuts, with the opposite end of the spring abutting the ledge |58 of the bracket |50, which bracket serves as a mount for the floor 54. A foot actuated lever |66 is pivoted intermediate its ends to a bracket |62, and one end of the lever lies underneath the head |54. Thus the pin |48 may be pushed upwardly through the medium of the foot controlled lever |60 for pushing the lever into the bore |52 so as to latch the bar 48 against relative movement. Wall |52 is so located as to bring the pin |48 therein when the wheels 64 and 66 have complete clearance from their respective drive wheels 44 and 46, thus permitting free manipulation of the control stick |02.

Power unit 28 comprises two electric motors |64 and |66 mounted inside the fuselage and the armature of each motor connected with a shaft |68 provided with a pinion |10 arranged in mesh with a rack |12 slidable longitudinally in a fixed guide |14. Rack |12 is interposed `in the control wire |16, with the wirev severed and connected with the ends of the rack vas at |18. Wire |16 connects with the horns '|86 of the elevators 30, while the usual second control wire |82 connects with the horns |64. Wires |16 and |82 are connected with the control stick |02 in the usual manner.

A batteryv |88 is connectedwith a switch |90 through the medium of a wire |62. A wire |84 leads from the battery |88 to the motor |64, and in the .wire I interpose a switch |96 which is manually controlled and remains closed during the operating period of the unit 26. A wire |98 leads from the motor |64 to the switch |96, and the latter is connected with a wire 260 which leads to the motor |66. A wire 202 leads from the motor |66 to the wire |94. The control rod |22 of the unit i8 is operatively connected with the switch |60 so as to close the circuit through the motor |66 when the rod is advanced forwardly through the medium of the weight i4. Sirmlarly, rearward movement of the rod closes the circuit to the motor |64.

Element |8 is brought into play whenever the airplane rotates about a transverse axis for selectively controlling the motors |64 and |66 to manipulate the elevators 3|). vThe circuits through the motors |64 and |66 can be closed one at a time only. As an example, a forward shift of the rod |22 will. energize the motor |66 and rotate the pinion |10 in such direction as to move the rack |68 forwardly to pivot the elevators to pivot downwardly for bringing the plane back to normal night. Should the tail of the plane rise, the control rod |22 would be shifted rearwardly for closing the circuit through the motor |64, which motor would rotate the vpinion |16 in the opposite direction and advance the rack |68 to pivot the elevators in the opposite direction, thus bringing the plane back to level flight.

In Figures 7 and 8, I illustrate a slightly different form of construction for the Weight pendulums 204. An inverted U-shaped member 205 is welded inside a tube 203. This tube is positioned inside an outer tube 2l0, and the two tubes are fashioned to provide roller bearings 2l2 positioned between the two ends of the two tubes. Inner tube 208 is threaded at.. 2l4 for connection with the rings 216 comprising portions of the bearings 2l2 for holding the two tubes in assembled relation. The rack 2l8 is slidable inside the member 205 and is supported by roller bearings 220. The pendulum 204 pivots about the shaft 222 in the samernanner as the pendulum H4. Flanges 224 on the outer tube 2|0 are xedly related to supports 226. In-

` ner tube 208 is arranged to rotate freely inside the tube 2l!) to permit the pendulum to assume true vertical positions.

I claim:

1. A stabilizer for airplanes having flight controls, power means, gravity sensitive means for operatively connecting the flight controls andthe power means when the airplane deviatesfrom level flight, to bring the airplane back to level flight, said gravity sensitive means including a tubular support, an inner tube rotatably related to the tubular support, and a gravity responsive weight pivotal inside the inner tube for rotation about an horizontal axis, the weight of the gravity sensitive weight turning the inner tube for maintaining said axis horizontal in all angular positions of the airplane.

2. A stabilizer for airplanes having flight controls, power means, gravity sensitive means for operatively connecting the flight controls and the power means when the airplane deviates from level flight, to bring the airplane back to level flight, said gravity sensitive means including a rotary bar support, and a gravity sensitive weight pivoted to the support for rotation about an horizontal axis, the load of the weight rotating the support for maintaining said axis horizontal in all angular positions of the airplane.

3. A stabilizer for airplanes having aileron controls, a driven shaft, friction rollers driven by the shaft in opposite direction, friction rollers carried by the aileron controls, a gravity responsive means for moving one of the last mentioned friction rollers into engagement with one of the friction rollers carried by the driven shaft for moving the aileron controls in one direction, said gravity responsive means when moved in another direction causes the other friction roller of the driven shaft to engage the other roller of the aileron controls for moving the aileron controls in the opposite direction, and means for rendering the gravity responsive means inoperative to permit manual control of the aileron controls.

4. A stabilizer for airplanes having elevator and aileron controls, a pair of electric motors, means operated by the motors for operatingy the elevator control, gravity responsive means for closing the circuit to one motor when the airplane deviates upwardly and closing the circuit to the other motor when the airplane deviates downwardly, a power shaft driven by the motor of the airplane, friction rollers driven by the power shaft, friction rollers carried by the aileron controls, and gravity responsive means for moving the last mentioned friction roller into engagement with the friction rollers carried by the power shaft.

5. A stabilizer for airplanes having aileron controls, a power shaft driven by the motor of the airplane, friction rollers driven by the power shaft, friction rollers carried by the aileron controls, a gravity responsive means comprising `a rigidly supported cylindrical member, a cylindrical member rotatably supported in the first cylindrical member, an intermediately pivoted Weight carried by the inner cylindrical member, and means operated by the upper end of the intermediately pivoted weight for moving the friction rollers carried by the aileron controls into and out of engagement with the friction rollers driven by the power shaft.

6. A stabilizer for airplanes having aileron controls, two spaced friction rollers driven in opposite directions by the power shaft driven by the motor of the airplane, a longitudinally movable bar, friction rollers carried by said bar and adapted to separately engage the spaced friction rollers, means carried by the shafts of the friction rollers carried by the bar for operating the aileron controls, and gravity responsive means connectedto the said bar for moving one of the rollers into engagement with one of the spaced friction rollers according to the direction of movement of the gravity responsive means.

7. A stabilizer for airplanes having aileron controls, two spaced friction rollers driven in opposite directions by the power shaft driven by the motor of the airplane, a longitudinally movable bar, friction rollers carried by the ends of said bar and adapted to engage either one of the spaced friction rollers, gears carried by the shafts of the rollers carried by the bar, a rack longitudinally movable and engaging said gears, connections between the ends of the rack and the aileron controls, and gravity responsive means connected to the ends of the longitudinally movable bar formoving one of the rollers carried thereby into engagement with one of the spaced driven rollers according to the direction of movement of the gravity responsive means.

RALPH A. OPENSHAW. 

